P0717

P0717 sets when the TCM commands the engine to be running and producing torque (engine RPM above roughly 400) but the input/turbine speed sensor reports zero RPM for 3-5 seconds, which is mechanically impossible unless the sensor has failed, the wiring is open, the tone-wheel/reluctor on the input shaft is damaged, or the torque converter is slipping catastrophically. This is the same diagnostic family as P0715 (which is the generic input speed sensor code), P0717 specifically calls out the no-signal condition rather than a range/performance issue. Cheapest-first ladder: scan live data and watch input/turbine RPM against engine RPM with the trans in park, healthy turbine RPM should track engine RPM within 50 RPM at idle with the converter unlocked; drop into drive and watch turbine RPM hold steady around 600-700 in gear while engine sits at 700-800. A flat zero reading from the turbine sensor confirms the no-signal condition. Verify the sensor connector at the trans case is seated and dry, ohm the sensor (typical inductive pickup is 250-1,500 ohms depending on platform, Hall-effect sensors are not resistance-checkable and require a 12V supply test), and inspect for ATF in the connector. Expensive misdiagnosis: do not authorize a transmission R&R for a reluctor-ring inspection until you have actually scoped the sensor signal during a road test, the most common root cause on 80% of platforms is a $40-90 sensor or a $30 connector pigtail, not an internal failure.

Vehicle-specific patterns: 2004-2009 Cadillac CTS/STS with 5L40E sees P0717 from input speed sensor failures, the sensor is externally serviceable on top of the case; 2007-2012 Nissan Altima/Maxima CVT (JATCO RE0F09/10) throws P0717 from primary pulley speed sensor failure, often alongside P0715 and P0776, NTB11-001 documents the diagnostic flow; 2003-2007 Honda Accord/Pilot 5AT (B7TA, BAYA) has a chronic 3rd-clutch-pressure-switch and dual-speed-sensor failure pattern where both input and counter shaft sensors fail in sequence. Estimated repair: $180 to $1,400.